Ubiquitous network technologies representatively comprise a radio frequency identification (RFID) technology or a ZigBee technology.
In an RFID network, a reader or an access point (AP) periodically transmits an information request signal. A tag entering a coverage area of the reader transmits tag information according to the information request signal of the reader. The reader checks the tag information received from the tag to communicate with the tag.
In such an RFID network, the reader can determine only if the tag exists in the coverage area of the reader according to the response of the tag, but cannot accurately detect position information of the tag. Accordingly, the reader periodically transmits the information request signal to the tag regardless of the existence of the tag. Therefore, power may be wasted.
In addition, the reader cannot select the tag that is the other party of communication. Accordingly, when the tag exists in a coverage area of the reader, the reader may unnecessarily communicate with the tag.